Extractive Electrospray
Ionization (EESI) mass spectrometry is a method for the ionization
of neutral analytes in complex matrices. EESI does not suffer from ion
suppression effects which is common for traditional electrospray
ionization (ESI). Recently we established EESI-QTOF MS platform for the direct
analysis of vaporized samples. This opened the way for new applications
such as direct analysis of breath for clinical diagnosis, rapid detectetion of trace amount of chemicals in various complex fluids. Futhermore, desorption
of analytes from surfaces with a gentle gas stream allows also
the fast and efficient investigation of biological samples or
the detection of explosives from surfaces in real time. For EESI
a solvent is electrosprayed while the sample is introduced
as vapor. Charge is transferred from the electrospray plume to
the analytes which leads to their ionization. A prinicipal scheme
of an typical EESI source is shown in the next figure:

figure: EESI
source: vaporized sample is introduced into a commercial ESI source
Projects:
Personnel:
| Lukas Meier started his Ph.D. in May 2009 after obtaining his M.Sc. degree in Chemistry at ETH Zürich with a focus on analytical chemistry. During his master thesis he worked on the epitope mapping project using MALDI-MS. If there is time to spare, he likes playing Handball, reading and spending time with friends. |
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Dr. Wai Siang Law obtained his PhD from National University of Singapore (NUS) in year 2008. He worked as a research assistant in NUS. He joined our group in September 2008 as a Postdoc with a ESKAS fellowship for the EESI project. |
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Christian Berchtold made his bachelor thesis at the criminal science institute and finished his master thesis at University of Basel in cooperation with Novartis in 2008. Since his apprenticeship he was working on food and drug analytics with mainly HPLC and LC-MS. In his spare time he is volunteer firefighter, likes skiing, traveling and spending time with his friends. |
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Dr. Huanwen Chen has received his Ph. D. in 2001 from Jilin University (China). After working in both instrumentation and chemistry in Prof. Cooks group at Purdue University (USA) he joined our group in March 2006 with a Simon Fellowship. Now he works on FT-ICR to monitor protein conformational changes in the gas phase, but also in our metabolomics project. |
Contact:
Dr. Wai Siang Law, law@org.chem.ethz.ch
Christian Berchtold, berchtold@org.chem.ethz.ch
Dr. Huanwen Chen, hchen@org.chem.ethz.ch
Prof. Dr. Renato Zenobi, zenobi@org.chem.ethz.ch